Electrically powered can opener

ABSTRACT

An electrically powered can opener has a lever pivoted on a housing, a linearly movable member carrying a circular cutter and a connecting means pivotally connecting the lever and the movable member. By depressing the lever, the cutter can be made to pierce into a can lid of a can at right angles immediately inside of the end rim of the can. The lever is held automatically at its cutter piercing position by a reaction force of a can opening operation.

United States Patent [191 Yamamoto et al.

' 1 Mar. 26, 1974 ELECTRICALLY POWERED CAN OPENER [75] Inventors: Osamu Yamamoto, Nagoya; Tatsuo Niwa, Kuwana-gun, both of Japan [73] Assignec: Kabushiki Kaisha Aichidenkikosakusho, Aichi-ken. Japan I22] Filed: June s, 1972 [Zl Appl. No.: 260,834

McLean 30/4 R Swanke 30/4 R FOREIGN PATENTS OR APPLICATIONS.

242,100 ll/l925 Great Britain 30/9 Primary ExaminerOthell M. Simpson Assistant Examiner-Gary b Smith ABSTRACT An electrically powered can openerhas a lever piv oted on a housing, a linearly movable member carrying a circular cutter and a connecting means pivotally connecting the lever and the movable member. By depressing the lever. the-cutter can be made to pierce into a can lid of a can at right angles immediately inside of the end rirnof the can. The lever is held automatically at its cutter piercing position by a reaction force of a can opening operation.

3 Claims, 9 Drawing Figures lllllllll l min m 2 34 k 8 1 3( 38 34 PATENTED MR 2 6 I974 SHEET 2 [IF 5 PATENTEDHARZS i974 I saw u or 5 mwmwmmwmgm &

FIG.6

PATENTEI] MAR 26 I974 SHEEI 5 0F 5 1 ELECTRICALLY POWERED CAN OPENER BACKGROUND OF THE INVENTION This invention relates to an electrically powered can opener including a driving wheel mounted on a housing front member for feeding a can and a lever pivoted thereon. The pivot point of the lever is so positioned on the front member that the reaction force exerted to a cutter cutting a can lid rotated by the driving wheel may act to rotate thelever to a cutter piercing position during a can opening operation and the lever can be held automatically by the reaction force applied to the cutter when the can opener is in operation.

With this kind of can opener, the pivot point of the lever on the housing is positioned over the cutter and so the cutter must be revolved around the pivot point of the lever in order to pierce the cutter into the can lid inside of an end rim disposed on a driving wheel. Accordingly the edge of the cutter is brought to the can lid from the outside of the end rim crossing the same. Because of the finite height of the end rim, it has been impossible to dispose the cutter closely at the immediate inside of the end rim. If the can lid is cut off along a circle considerably apart from the can rim, some inconveniences are brought about in taking out canned foods and fingers of an operator may be injured by the edge of the uncut remainder of the can lid.

SUMMARY OF THE INVENTION A can opener according to the present invention is provided to eliminate such points as described andis characterized by that a shaft of a rotary cutter op erably engaged with a lever is actuated at right angles to a can lid to be cut off by operating the lever. The cutter shaft is, in stead of being ordinarily mounted on the lever, movable along a linear guiding member secured on a housing or a base removably mountable on the housing and is connected pivotally to the lever by a connecting rod. In the situation where the cutter is cutting the can lid, the lever is rotated in a cutter piercing direction at least to the extent that the pivot point of the lever and the connecting rod reaches a line through the center of the cutter shaft and the pivot point of the lever on the housing. With this'arrangement, the component of the reaction force generated in the can opening operation, which lies in the direction of the movement of the cutter shaft, acts further to rotate the lever in the cutter piercing direction and the cutter is held in the can opening position with cooperation with the housing or a suitable stopper mounted thereon. A switch connected in an electric circuit for a driving motor is maintained closed by some part of the lever thus held in the can opening position. If the reaction force of the can opening operation disappears, then the lever is re turned to the former position by a suitable restoring member having a biasing force weaker than the reaction force and the switch is opened, too. The biasing force of thisrestoring member can be made adjustable.

The salient relationships of the present invention have been described and it is understood that a can opener according to the present invention, which is one being held automatically by the reaction force of the can opening operation in the can opening position, can actuate cutter at right angles with respect to a can lid when the lever is operated. Thus, the cutting off of a can lid at the immediate inside of an end rim is facilitated without loosing the advantages of the present kind of can openers i.e., the automatic holding of the lever by the reaction force and the automatic stop of the can opener at the end of the can opening operation.

IN THE DRAWINGS FIG. 1 is a front elevation of a can opener.

FIG. 2 is a partial enlarged view of section taken along the line 22;

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 1.

FIG. 4 is a partial rear view viewed from the right hand side of FIG. 3.

FIG. 5 is an enlarged sectional view showing significant portions of the can opener.

FIG. 6 is a front elevational view of'a modification of the can opener.

FIG. 7 is a section taken along the line 7-7 of FIG. 6.

FIG. 8 is a partial view of section showing the relationship between a lever and a cutter of the can opener shown in FIG. 6.

FIG. 9 is a section taken along the line 99 of FIG. 7.

Referring to FIGS. 1-5, a can stand 10 has a form suitable to be disposed on an ordinary table for example. A tightening screw 11 is engaged threadably through an arm 12 extending integrally from the can stand 10 and has a tightening head 13 at its upper end and a hand grip 14 at its lower end. In the rear portion of the can stand 10 is'bored an axial hole 15, in which a stay 16 is inserted for vertical movement. By means of a set screw 17 the stay 16 can be fixed at an arbitrary height. In a housing 18 threadably mounted on the top of the stay 16,-an electric motor 19 is mounted fixedly and a series of reduction gears 20-25 are disposed for the purpose of transmitting the rotation of the motor 19 to a driving shaft 26 to be described hereafter and parts of the gears represented by numerals 23 and 25 are omitted for the convenience of viewing the drawings. On one end of driving shaft 26 is mounted a toothed driving wheel 27 adapted to be in contact with the lower edge of a can and to feed an end rim of the can. On the front member'of the housing 18, one end portion of a lever 28 is pivoted by a pivot pin 29 and the other end portion 28' of the lever serves as a grip. A circular cutter 30 is mounted rotatably on a cutter shaft 32 extending from a base 31 by a screw 33. The base 31 is fitted slidably for vertical movement on a pair of guide rails 34 secured on the housing 18.- The lever 28 and the base 31 are connected pivotally to both ends of a connecting rod 35 by pins 36 and 37 respectively. Thus, the base 31 can be moved vertically along the guide rails 34 by lowering the grip portion 28 of the lever 28. In order tofacilitate the automatic holding of the lever 28 by a reaction force generated in a can opening operation, the lever 28 must be rotated at least to the extent that the pin 36 is brought to a line through the pin 37 and the pivot pin 29 when the cutter 30 is piercing in a can lid. From the base 31 there is extending an expandable arm 38 on which a can lid attracting magnet 39 is attached. The expandable arm 38 comprises four links 40 connected pivotally by screws 41 in the form of a parallelogram and is adapted to displace the magnet 39 to the left or the right hand side of FIG. 3. In FIG. 5 is shown an adjustable restoring means 42 for the lever 28. This comprises a pushing up bar 43 made movable within a certain stroke, a stop ring 44 for limiting the stroke of the pushing up bar 43, a coil spring 46 inserted in a hole 45 bored through the housing 18 and an adjusting screw 47 fitted threadably in the inlet portion of the hole 45. The compression of the coil spring 46 can be adjusted by displacing the adjusting screw 47 in the axial direction of the hole 45. The biasing force of the spring 46 is adjusted to be weaker than the component of the reaction force acting to hold the lever 28 in the cutter piercing position but sufficiently strong to raise the lever 28 by a certain small height equal to a stroke of a movable piece of a switch 48 connected in a driving motorcircuit, when the reaction force disappears. Switch 48 is connected in a driving motor circuit and is disposed at a position where a movable piece 49 of the switch 48 can be closed by the lever 28 in the depressed position. The switch 48 is maintained closed when the cutter 30 is pierced in the can lid and becomes opened when the lever 28 is raised by the coil spring 46.

Next, the method of using the can opener thus constructed is described. Firstly, the can stand is placed on a table and fixed there by means of the tightening screw 11. The vertical position of.the stay 16 is adjusted according to sizes of cans and the lower portion of an end rim of a can is made to be in contact with the top of the driving wheel 27. Then the lever 28 is lowered. The base 31 and the circular cutter 30 are lowered at right angles to the can lid and the cutter 30 pierces into the can lid immediately inside of the end rim. Thus, the can lid can be cut off at its outermost portion thereby broadening a cut out opening to facilitate taking out of canned foods and a small portion of the can lid remains uncut thereby preventing the operators hand from being injured. At the same time, the movable piece 49 is depressed by the lever 28 to close the switch 48 and the motor 19 is started. The driving wheel 27 is rotated in a direction indicated by an arrow 50 to feed the can. As the can is thus fed, the cutter 30 is subjected to a reaction force in an obliquely up- .ward and left hand direction of FIG. 5. and certain component thereof acts to raise the base 31. As is seen in FIG. 5, this component results in lowering the lever 28 which is prevented from rotating by the housing 18,- in a direction shown by an arrow 5lbecause the pin 36 is under the line through the pivot pin 29 and the pin 37 in FIG. 5 when the lever 28 is in the lower position and consequentlythe lever 28 is held automatically in the lower position. The operator can detach his hands from the can opener. When a continuous can opening operation with this situation is finished, the reaction force applied to the cutter 30 from the can lid, hence said component thereof disappears. At this time, the lever 28 is raised by the restoring force of the spring 46 within the stroke of the pushing up bar 43. As the result, the movable piece 49 is raised to open the switch 48 and the motor is deenergized. In this siutation, the lever 28 is raised only slightly and so the can is held by the cooperation of the driving wheel 27 and the cutter 30 and is prevented from dropping from the can opener. If the cut out can is to be taken away, the base 31 and the cutter 30 are raised by raising the lever 28 and the can is in position to be taken away. If the reaction force of the can opening operation changes according to sizes or materials of cans to be opened, the biasing force of the restoring means 42 can be adjusted by operating the adjusting screw 47. Thus, in opening all kinds of cans, undesirable misoperations resulting from the unbalance of the restoring force and the reaction force such as an accidental rising up of the lever 28 during a can opening operation and a failure of rising up of the lever 28 after a can opening operation can be avoided.

Next, referring to FIGS. 6-9, another embodiment is described. On a front member 52' of a housing member 52 is formed a depressed portion 53 and a driving shaft bearing portion 79 is'disposed horizontally in the housing 52. Under the bearing portion 79 there is a can guide 54 extending from the front member 52' outwardly of the housing 52. A lever 55 with an integral grip portion 55 is pivoted on a base 56 by means of a headed pivot 57. The pivotal mounting of the lever 55 is effected by passing the headed pivot 57- through the lever 55, a washer 58 and the base 56 and attaching a nut 59 threadably to the headed pivot 57. A cutter shaft 60 extends obliquely downward from a movable member 61 which is adapted slidably in an elongate guiding slot 62 formed through the base 56. A circular cutter 63 is mounted rotatably on the lower end of the cutter shaft 60 by means of a screw 64. The base 56 has a form suitable to be detachably mounted in the depressed portion 53. A pair of latch members 65 extend from both sides of the base 56 at right angles to the surface of it and are adapted to be inserted through mating openings 66 bored through the front'member 52', the end portions of the latch members 65 being narrowed as shown. The lower edges of latch members 65 areprovided with latching cuts 67. On the surface of the depressed portion 53 is secured a push-out spring 68 which acts to bias the base 56 forwardly of the housing 52 when the base 56 is in the depressed portion 53. Next, a can feeding mechanism is described. In a hole 69 bored through the base 56 is inserted a holder 70 loosely, the headed portion of which is peripherally toothed and serves as a driving wheel 76 protruding from the from member 52. A mating groove 71 is formed on the inner end portion of the holder 70 and an axial hole 72 is bored along the axis of the holder 70. The outer diameter of the holder 70 is made con siderably smaller than the diameter of the hole 69 so that the holder 70 may be inserted in the hole 69 without contacting the edge of the hole 69. In a circular groove 73 there is positioned a C-shaped ring 74 for the purpose of preventing the detachment of the holder 70 and a polisliderwasher 75 is disposed between the headed portion of the holder 70 and the base 56. When the base 56 and the lever 55 are mounted on the corresponding positions of the front member 52', the lower edge of the circular cutter 63 is made to come over and slightly forwardly of the driving wheel 76 described. 0n the front end of a driving shaft 77 is formed an integral connecting member 78 having a form for insertion in the axial hole 72 of the holder 70. The end portion of thedriving shaft 77 has a form complementary with the mating groove 71, thereby transmitting the torque from an electric motor to the driving wheel 76. On the other end portion of the driving shaft 77 extending beyond the bearing portion 79 is secured a gear 80 by means of a nut 81 and a planar spring 82 is provided in the housing 52 so as to bias the tip of the driving shaft 77 extending further beyond the gear 80 towards the front member 52'. An electric motor is mounted in the housing 52 and is connected to the gear 80 through a well-known gear assembly. As is shown in FIG. 7, a locking member guide 83 having a L-shaped cross-section is secured on the inside surface of the front member 52' under the bearing portion 79 and a pair of guiding holes 84 are bored through the horizontal portion of the locking member guide 83. A locking member 85 has a pair of leg portions 86 suitable for slidable insertion in the guiding holes 84 at its lower end and an elongate hole 87 at its upper end. The leg portions 86 are inserted in theguiding holes 84 and the locking member 85 is mounted on the inside surface of the front member 52' by a screw 88 inserted in the elongate hole 87 for the vertical movement of the locking member 85 within the length of the elongate hole 87. A compression spring 89 is inserted com'pressingly between a spring seat provided on the locking member 85 and the bearing portion 79 and is biasing the locking member 85 upwards. A pair of latching openings 90 are bored through the locking member 85 and the lower edges thereof latch the latching cuts 67 when the latch members 65 are inserted through these latching openings 90. A push button 91 is attached on the top of the locking member 85 and is protrudable through the top member of the housing 52. A start push button 92 is protruding through thetop member of the housing 52 so as to be depressed by the grip portion 55' of the lever 55. To the start push button 92is connected an operating rod which operates a switch connected in the power supply circuit of the electric motor as in the conventional art.

Next, a description is given to a construction associated with the cutter 63 actuated vertically with the rotation of the lever 55. As shown in the drawings, the movable member 61 threadably carrying the cutter shaft 60 is disposed slidably in the guiding slot 62. Both side surfaces 94 of the movable member 61 are made flat so as to be in close contact with the side walls of the guiding slot 62, thereby preventing the rotation and the pitching of the movable member 61. The fall away of the movable member 61 is prevented by means of a washer 95 and a nut 96. The lever 55 and the movable member 61 are connected by a connecting rod 97 provided with holes 98 and 98' at both ends thereof. The lever 55 is pivoted on the connecting rod 97 by means of a headed bolt 99 inserted through the hole 98 and a nut 100 threadably attached to the bolt 99. The pivotal connection between the movable member 61 and the connecting rod 97 is effectuated by inserting a neck portion 101 of the movable member 61 in the hole 98'.

The use of the can opener thus constructed is described. When the lever 55 and the base 56 united by the pivot 57 are to be mounted on the housing 52 as shown in FIG. 8, the latch members 65 are inserted in the mating openings 66 and the base 56 is pushed towards the front member 52'. When the narrowed ends of the members 65 begin to enter the latching openings 90, these ends depress the locking member 85 downwards against the force of the compression spring 89. At the same time, the connecting member 78 of the driving shaft 77 begins to enter the axial hole 72 of the holder 70. As these movements proceed, the latching cuts 67 are latched by the lower edges of the latching openings 90 and the locking member is returned upwards by the depth of the latching engagement, thereby mounting the lever 55 together with the base 56 on the housing 52. At this time, the complimentary flattened end portion of the driving shaft 77 may mate with the mating groove 71 by chance but in most cases, they do not mate with each other because their angular positions are not necessarily favorable for the mating. The distance resulting from the mismating between them is compensated by the axial displacement of the driving shaft 77 against the planar spring 82 and the driving shaft 77 is, in turn, biased by the planar spring 82. The end portion of the shaft 77 and the groove 71 are brought into mating by the biasing force of the planar spring 82 when the shaft 77 is rotated to make an angular position favorable for the mating. If an end rim of a can to be opened is brought on the driving wheel 76 with the lever 55 and base 56 thus mounted on the housing 52, and the lever 55 is lowered by depressing the grip portion 55, thestart push button 92 is depressed to act to rotate the driving shaft 77 as in a wellknown manner. The driving wheel 76 is rotated under the support of the driving shaft 77 immediately if the driving shaft 77 is rnating with the mating groove 71 or after only the driving shaft 77 is rotated to establish the mating engagement between the driving shaft 77 and the mating groove 71 under the force of the planar spring 82 if they are not mating with each other. During the downward movement of the grip portion 55' to the position shown in FIG. 6, the movable member 61 connected to the lever 55 by the connecting rod 97 is lowered along the guiding slot 62. As the result, the edge of the circular cutter 63can contact a can lid immediately inside of the end rim of the can and the cutter 63 is rotated around the cutter shaft 60 on account of the actuation of the can by the driving wheel 76. The lever 55 is rotated further towards the can by the reaction force applied to the cutter 63 and the cutter is pierced into the can lid to continue a can opening operation. The positional relation among the pivot 57, the bolt 99 and the movable member 61 with the lever 55 at the cutter piercing position is similar to that among the pivot pin 29, the pin 36 and the pin 37 of the first embodiment. When the can opening operation is finished, the cutter piercing component of the reaction force disappears and the grip portion 55' is raised slightly by a suitably provided return spring to make free the start push button 92. Thus, the electric motor is stopped. By raising the grip portion 55' further, the movable member 61 is raised vertically by the connecting rod 97 to an arbitrary position. The opened can is in position to be taken away.

Although the present invention has been described with preferred embodiments, it should be understood that many changes and modifications are possible to the present invention without departing from the spirits and the scope of the following claims of the present invention. 5

We claim I 1. An electrically powered can opener comprising a housing, an electric motor mounted in said housing, a driving wheel extending rotatably through said housing, said driving wheel being actuated from said electric motor, a lever pivoted on said housing over said driving wheel, a linear guiding member secured on said housing, a base mounted slidably on said linear guiding member for the vertical movement of said base, a cutter shaft carried by said base, a cutter mounted rotatably on said cutter shaft, a connecting member pivotally connecting said lever and said base, the pivot point of said lever on said housing being so determined as to facilitate the automatic holding of said lever in a cutter piercing position due to the reaction force of a can opening operation applied to said cutter, said lever in the cutter piercing position being rotated at least to the extent that the pivot point between said lever and said connecting member is brought to a line through the pivot point between said lever and said housing and the center of said cutter shaft, a restoring means engaging with said lever in the cutter piercing position and a switch connected in an electric circuit for said motor, said switch being disposed so as to be operated by said lever in the cutter piercing position.

2. An electrically powered can opener as described in claim 1 in which the biasing force of said restoring means is adjustable.

3. An electrically powered can opener comprising a housing having a front member with a depressed portion, an electric motor mounted in said housing, a base having a form suitable for being detachably mounted in said depressed portion, a lever pivoted on said base,

a driving wheel extending rotatably through said base under said lever, said driving wheel being connected separably to said electric motor through said housing, a linear guiding member formed in said base,, a movable member adapted slidably in said linear guiding member for the vertical movement of said base, a cutter shaft carried by said movable member, a cutter mounted rotatably on said cutter shaft, a connecting member pivotally connecting said lever and said movable member, the pivot point of said lever on said base being so determined as to facilitate the automatic holding of said lever in a cutter piercing position due to the reaction force of a can opening operation applied to said cutter, said lever in the cutter piercing position being rotated at least to the extent that the pivot between said lever and said connecting member is brought to a line through the pivot point between said lever and said base and the center of said cutter shaft, a restoring means engaging with said lever in the cutter piercing position and a switch connected in an electric circuit for said motor, said switch being disposed so as to be operated by said lever in the cutter piercing position. 

1. An electrically powered can opener comprising a housing, an electric motor mounted in said housing, a driving wheel extending rotatably through said housing, said driving wheel being actuated from said electric motor, a lever pivoted on said housing over said driving wheel, a linear guiding member secured on said housing, a base mounted slidably on said linear guiding member for the vertical movement of said base, a cutter shaft carried by said base, a cutter mounted rotatably on said cutter shaft, a connecting member pivotally connecting said lever and said base, the pivot point of said lever on said housing being so determined as to facilitate the automatic holding of said lever in a cutter piercing position due to the reaction force of a can opening operation applied to said cutter, said lever in the cutter piercing position being rotated at least to the extent that the pivot point between said lever and said connecting member is brought to a line through the pivot point between said lever and said housing and the center of said cutter shaft, a restoring means engaging with said lever in the cutter piercing position and a switch connected in an electric circuit for said motor, said switch being disposed so as to be operated by said lever in the cutter piercing position.
 2. An electrically powered can opener as described in claim 1 in which the biasing force of said restoring means is adjustable.
 3. An electrically powered can opener comprising a housing having a front member with a depressed portion, an electric motor mounted in said housing, a base having a form suitable for being detachably mounted in said depressed portion, a lever pivoted on said base, a driving wheel extending rotatably through said base under said lever, said driving wheel being connected separably to said electric motor through said housing, a linear guiding member formed in said base,, a movable member adapted slidably in said linear guiding member for the vertical movement of said base, a cutter shaft carried by said movable member, a cutter mounted rotatably on said cutter shaft, a connecting member pivotally connecting said lever and said movable member, the pivot point of said lever on said base being so determined as to facilitate the automatic holding of said lever in a cutter piercing position due to the reaction force of a can opening operation applied to said cutter, said lever in the cutter piercing position being rotated at least to the extent that the pivot between said lever and said connecting member is brought to a line through the pivot point between said lever and said base and the center of said cutter shaft, a restoring means engaging with said lever in the cutter piErcing position and a switch connected in an electric circuit for said motor, said switch being disposed so as to be operated by said lever in the cutter piercing position. 